<ol>
  <li>Type the arc radius into the options tool bar and choose the arc
  direction (clockwise or counter-clockwise) and the solution (larger arc or
  smaller arc).</li>
  <li>Specify the start point of the arc.</li>
  <li>Specify the end point of the arc. If the end point is too far away from
  the start point for a solution, the closest solution is drawn (a half circle
  with the given radius and direction).</li>
</ol>
